Changing monsoon trend forces Met dept to offer Aug forecast

New Delhi: India’s weather department will now provide rain forecast for August because of higher rainfall in this month in several parts of the country in the past few years, a top official said.

This is expected to help farmers plan their sowing season by adjusting to the changing pattern of the monsoon. The India Meteorological Department (IMD) currently offers rain forecast only for July, which has seen a decline in rainfall for nearly a decade.

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“July is still the rainiest month. However, the rainfall in August is becoming important and we’ve been getting several demands from farmers and agricultural universities to provide forecast for August,” said D.S. Pai, a director of IMD. Pai, based in Pune, is in charge of preparing the annual monsoon forecast.

Several scientists have independently reported a fall in precipitation in July and a rise in August over large swathes of India in the past few years, he said.

The June-September monsoon season in India accounts for nearly 80% of the annual rainfall. It is vital for the economy because farm output—which generates 17% of the nation’s GDP and employs around 60% of its workers—largely depends on it.

Typically, July contributes a quarter of the annual rain, followed by August, which contributes a fifth.

However, scientists have said it is likely that August could become the rainiest month in the next few years, Pai said. This means farmers may have to delay or advance sowing of different crops.

An economist said the effects of increased rainfall in a particular month is more pronounced in irrigated agriculture. “The Punjab government, for instance, bans its farmers from sowing their kharif (summer) crop before June,” said Himanshu, an economist at the Jawaharlal Nehru University and a Mint columnist. “This is to prevent farmers from overdrawing groundwater and affecting the already precarious water table. So changing monsoon patterns mean policies will also change.”

As reported by Mint on 18 August, Nityanand Singh and his colleagues at the Indian Institute of Tropical Meteorology, an autonomous research institute, analysed rainfall trends between 1813 and 2006, which showed that there is a decreasing trend in rainfall received by at least two-thirds of India, and that the contribution of the monsoon months to annual rainfall has been falling.

“This is part of a natural variation,” Pai said, adding that the variability in sea surface temperatures in the Indian Ocean and the Pacific Ocean had a crucial role to play, but the exact reasons are unknown.

IMD has had a test model for forecasting the rainfall in August for a few years now. “We’ve had it for a few years, but weren’t too satisfied with it,” said Pai. “We’ve made some improvements. And this time we’ve decided to be bold and give it a try.”